Annotation of src/usr.bin/ssh/kex.c, Revision 1.65
1.1 markus 1: /*
1.36 markus 2: * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
1.1 markus 3: *
4: * Redistribution and use in source and binary forms, with or without
5: * modification, are permitted provided that the following conditions
6: * are met:
7: * 1. Redistributions of source code must retain the above copyright
8: * notice, this list of conditions and the following disclaimer.
9: * 2. Redistributions in binary form must reproduce the above copyright
10: * notice, this list of conditions and the following disclaimer in the
11: * documentation and/or other materials provided with the distribution.
12: *
13: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
14: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
15: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
16: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
17: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
18: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
19: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
20: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
21: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
22: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
23: */
24:
25: #include "includes.h"
1.65 ! djm 26: RCSID("$OpenBSD: kex.c,v 1.64 2005/07/25 11:59:39 markus Exp $");
1.18 markus 27:
28: #include <openssl/crypto.h>
1.1 markus 29:
30: #include "ssh2.h"
31: #include "xmalloc.h"
32: #include "buffer.h"
33: #include "bufaux.h"
1.7 markus 34: #include "packet.h"
1.1 markus 35: #include "compat.h"
1.18 markus 36: #include "cipher.h"
1.1 markus 37: #include "kex.h"
1.13 markus 38: #include "key.h"
1.18 markus 39: #include "log.h"
1.21 markus 40: #include "mac.h"
1.23 markus 41: #include "match.h"
1.26 markus 42: #include "dispatch.h"
1.48 provos 43: #include "monitor.h"
1.1 markus 44:
1.7 markus 45: #define KEX_COOKIE_LEN 16
1.48 provos 46:
1.35 itojun 47: /* prototype */
48: static void kex_kexinit_finish(Kex *);
49: static void kex_choose_conf(Kex *);
1.26 markus 50:
51: /* put algorithm proposal into buffer */
1.35 itojun 52: static void
1.26 markus 53: kex_prop2buf(Buffer *b, char *proposal[PROPOSAL_MAX])
1.1 markus 54: {
1.61 djm 55: u_int i;
1.26 markus 56:
57: buffer_clear(b);
1.49 markus 58: /*
59: * add a dummy cookie, the cookie will be overwritten by
60: * kex_send_kexinit(), each time a kexinit is set
61: */
62: for (i = 0; i < KEX_COOKIE_LEN; i++)
63: buffer_put_char(b, 0);
1.1 markus 64: for (i = 0; i < PROPOSAL_MAX; i++)
1.26 markus 65: buffer_put_cstring(b, proposal[i]);
66: buffer_put_char(b, 0); /* first_kex_packet_follows */
67: buffer_put_int(b, 0); /* uint32 reserved */
1.1 markus 68: }
69:
1.26 markus 70: /* parse buffer and return algorithm proposal */
1.35 itojun 71: static char **
1.53 markus 72: kex_buf2prop(Buffer *raw, int *first_kex_follows)
1.7 markus 73: {
1.26 markus 74: Buffer b;
1.7 markus 75: int i;
1.26 markus 76: char **proposal;
1.7 markus 77:
1.26 markus 78: proposal = xmalloc(PROPOSAL_MAX * sizeof(char *));
1.7 markus 79:
1.26 markus 80: buffer_init(&b);
81: buffer_append(&b, buffer_ptr(raw), buffer_len(raw));
1.7 markus 82: /* skip cookie */
83: for (i = 0; i < KEX_COOKIE_LEN; i++)
1.26 markus 84: buffer_get_char(&b);
1.7 markus 85: /* extract kex init proposal strings */
86: for (i = 0; i < PROPOSAL_MAX; i++) {
1.26 markus 87: proposal[i] = buffer_get_string(&b,NULL);
88: debug2("kex_parse_kexinit: %s", proposal[i]);
1.7 markus 89: }
1.26 markus 90: /* first kex follows / reserved */
91: i = buffer_get_char(&b);
1.53 markus 92: if (first_kex_follows != NULL)
93: *first_kex_follows = i;
1.26 markus 94: debug2("kex_parse_kexinit: first_kex_follows %d ", i);
95: i = buffer_get_int(&b);
96: debug2("kex_parse_kexinit: reserved %d ", i);
97: buffer_free(&b);
98: return proposal;
1.1 markus 99: }
100:
1.35 itojun 101: static void
1.26 markus 102: kex_prop_free(char **proposal)
1.1 markus 103: {
1.61 djm 104: u_int i;
1.26 markus 105:
106: for (i = 0; i < PROPOSAL_MAX; i++)
107: xfree(proposal[i]);
108: xfree(proposal);
1.1 markus 109: }
110:
1.35 itojun 111: static void
1.41 markus 112: kex_protocol_error(int type, u_int32_t seq, void *ctxt)
1.1 markus 113: {
1.41 markus 114: error("Hm, kex protocol error: type %d seq %u", type, seq);
1.26 markus 115: }
1.1 markus 116:
1.35 itojun 117: static void
1.44 markus 118: kex_reset_dispatch(void)
1.29 markus 119: {
1.42 markus 120: dispatch_range(SSH2_MSG_TRANSPORT_MIN,
121: SSH2_MSG_TRANSPORT_MAX, &kex_protocol_error);
1.44 markus 122: dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit);
1.29 markus 123: }
124:
125: void
1.28 markus 126: kex_finish(Kex *kex)
1.26 markus 127: {
1.44 markus 128: kex_reset_dispatch();
1.28 markus 129:
1.26 markus 130: packet_start(SSH2_MSG_NEWKEYS);
131: packet_send();
132: /* packet_write_wait(); */
133: debug("SSH2_MSG_NEWKEYS sent");
1.19 stevesk 134:
1.52 markus 135: debug("expecting SSH2_MSG_NEWKEYS");
1.40 markus 136: packet_read_expect(SSH2_MSG_NEWKEYS);
1.46 markus 137: packet_check_eom();
1.26 markus 138: debug("SSH2_MSG_NEWKEYS received");
1.32 markus 139:
1.30 markus 140: kex->done = 1;
1.26 markus 141: buffer_clear(&kex->peer);
1.27 markus 142: /* buffer_clear(&kex->my); */
1.26 markus 143: kex->flags &= ~KEX_INIT_SENT;
1.32 markus 144: xfree(kex->name);
145: kex->name = NULL;
1.26 markus 146: }
1.1 markus 147:
1.26 markus 148: void
149: kex_send_kexinit(Kex *kex)
150: {
1.60 avsm 151: u_int32_t rnd = 0;
1.49 markus 152: u_char *cookie;
1.61 djm 153: u_int i;
1.49 markus 154:
1.29 markus 155: if (kex == NULL) {
156: error("kex_send_kexinit: no kex, cannot rekey");
157: return;
158: }
1.28 markus 159: if (kex->flags & KEX_INIT_SENT) {
160: debug("KEX_INIT_SENT");
161: return;
162: }
1.30 markus 163: kex->done = 0;
1.49 markus 164:
165: /* generate a random cookie */
166: if (buffer_len(&kex->my) < KEX_COOKIE_LEN)
167: fatal("kex_send_kexinit: kex proposal too short");
168: cookie = buffer_ptr(&kex->my);
169: for (i = 0; i < KEX_COOKIE_LEN; i++) {
170: if (i % 4 == 0)
1.60 avsm 171: rnd = arc4random();
172: cookie[i] = rnd;
173: rnd >>= 8;
1.49 markus 174: }
1.26 markus 175: packet_start(SSH2_MSG_KEXINIT);
176: packet_put_raw(buffer_ptr(&kex->my), buffer_len(&kex->my));
177: packet_send();
178: debug("SSH2_MSG_KEXINIT sent");
179: kex->flags |= KEX_INIT_SENT;
1.1 markus 180: }
181:
1.26 markus 182: void
1.41 markus 183: kex_input_kexinit(int type, u_int32_t seq, void *ctxt)
1.11 provos 184: {
1.26 markus 185: char *ptr;
1.61 djm 186: u_int i, dlen;
1.26 markus 187: Kex *kex = (Kex *)ctxt;
1.11 provos 188:
1.26 markus 189: debug("SSH2_MSG_KEXINIT received");
1.29 markus 190: if (kex == NULL)
191: fatal("kex_input_kexinit: no kex, cannot rekey");
1.11 provos 192:
1.26 markus 193: ptr = packet_get_raw(&dlen);
194: buffer_append(&kex->peer, ptr, dlen);
1.31 markus 195:
196: /* discard packet */
197: for (i = 0; i < KEX_COOKIE_LEN; i++)
198: packet_get_char();
199: for (i = 0; i < PROPOSAL_MAX; i++)
200: xfree(packet_get_string(NULL));
1.51 markus 201: (void) packet_get_char();
202: (void) packet_get_int();
1.39 markus 203: packet_check_eom();
1.19 stevesk 204:
1.26 markus 205: kex_kexinit_finish(kex);
206: }
1.11 provos 207:
1.26 markus 208: Kex *
1.28 markus 209: kex_setup(char *proposal[PROPOSAL_MAX])
1.26 markus 210: {
211: Kex *kex;
1.11 provos 212:
1.26 markus 213: kex = xmalloc(sizeof(*kex));
214: memset(kex, 0, sizeof(*kex));
215: buffer_init(&kex->peer);
216: buffer_init(&kex->my);
217: kex_prop2buf(&kex->my, proposal);
1.30 markus 218: kex->done = 0;
1.26 markus 219:
220: kex_send_kexinit(kex); /* we start */
1.44 markus 221: kex_reset_dispatch();
1.26 markus 222:
223: return kex;
1.11 provos 224: }
225:
1.35 itojun 226: static void
1.26 markus 227: kex_kexinit_finish(Kex *kex)
1.1 markus 228: {
1.26 markus 229: if (!(kex->flags & KEX_INIT_SENT))
230: kex_send_kexinit(kex);
1.1 markus 231:
1.26 markus 232: kex_choose_conf(kex);
1.1 markus 233:
1.54 markus 234: if (kex->kex_type >= 0 && kex->kex_type < KEX_MAX &&
235: kex->kex[kex->kex_type] != NULL) {
236: (kex->kex[kex->kex_type])(kex);
237: } else {
1.26 markus 238: fatal("Unsupported key exchange %d", kex->kex_type);
1.1 markus 239: }
240: }
241:
1.35 itojun 242: static void
1.1 markus 243: choose_enc(Enc *enc, char *client, char *server)
244: {
1.23 markus 245: char *name = match_list(client, server, NULL);
1.1 markus 246: if (name == NULL)
247: fatal("no matching cipher found: client %s server %s", client, server);
1.45 markus 248: if ((enc->cipher = cipher_by_name(name)) == NULL)
1.12 markus 249: fatal("matching cipher is not supported: %s", name);
1.1 markus 250: enc->name = name;
251: enc->enabled = 0;
252: enc->iv = NULL;
253: enc->key = NULL;
1.45 markus 254: enc->key_len = cipher_keylen(enc->cipher);
255: enc->block_size = cipher_blocksize(enc->cipher);
1.1 markus 256: }
1.35 itojun 257: static void
1.1 markus 258: choose_mac(Mac *mac, char *client, char *server)
259: {
1.23 markus 260: char *name = match_list(client, server, NULL);
1.1 markus 261: if (name == NULL)
262: fatal("no matching mac found: client %s server %s", client, server);
1.21 markus 263: if (mac_init(mac, name) < 0)
1.1 markus 264: fatal("unsupported mac %s", name);
1.21 markus 265: /* truncate the key */
266: if (datafellows & SSH_BUG_HMAC)
267: mac->key_len = 16;
1.1 markus 268: mac->name = name;
269: mac->key = NULL;
270: mac->enabled = 0;
271: }
1.35 itojun 272: static void
1.1 markus 273: choose_comp(Comp *comp, char *client, char *server)
274: {
1.23 markus 275: char *name = match_list(client, server, NULL);
1.1 markus 276: if (name == NULL)
277: fatal("no matching comp found: client %s server %s", client, server);
1.64 markus 278: if (strcmp(name, "zlib@openssh.com") == 0) {
279: comp->type = COMP_DELAYED;
280: } else if (strcmp(name, "zlib") == 0) {
281: comp->type = COMP_ZLIB;
1.1 markus 282: } else if (strcmp(name, "none") == 0) {
1.64 markus 283: comp->type = COMP_NONE;
1.1 markus 284: } else {
285: fatal("unsupported comp %s", name);
286: }
287: comp->name = name;
288: }
1.35 itojun 289: static void
1.1 markus 290: choose_kex(Kex *k, char *client, char *server)
291: {
1.23 markus 292: k->name = match_list(client, server, NULL);
1.1 markus 293: if (k->name == NULL)
294: fatal("no kex alg");
1.11 provos 295: if (strcmp(k->name, KEX_DH1) == 0) {
1.54 markus 296: k->kex_type = KEX_DH_GRP1_SHA1;
1.65 ! djm 297: k->evp_md = EVP_sha1();
1.59 djm 298: } else if (strcmp(k->name, KEX_DH14) == 0) {
299: k->kex_type = KEX_DH_GRP14_SHA1;
1.65 ! djm 300: k->evp_md = EVP_sha1();
! 301: } else if (strcmp(k->name, KEX_DHGEX_SHA1) == 0) {
1.54 markus 302: k->kex_type = KEX_DH_GEX_SHA1;
1.65 ! djm 303: k->evp_md = EVP_sha1();
1.11 provos 304: } else
1.1 markus 305: fatal("bad kex alg %s", k->name);
306: }
1.65 ! djm 307:
1.35 itojun 308: static void
1.1 markus 309: choose_hostkeyalg(Kex *k, char *client, char *server)
310: {
1.23 markus 311: char *hostkeyalg = match_list(client, server, NULL);
1.13 markus 312: if (hostkeyalg == NULL)
1.1 markus 313: fatal("no hostkey alg");
1.13 markus 314: k->hostkey_type = key_type_from_name(hostkeyalg);
315: if (k->hostkey_type == KEY_UNSPEC)
316: fatal("bad hostkey alg '%s'", hostkeyalg);
1.17 markus 317: xfree(hostkeyalg);
1.1 markus 318: }
319:
1.56 djm 320: static int
1.53 markus 321: proposals_match(char *my[PROPOSAL_MAX], char *peer[PROPOSAL_MAX])
322: {
323: static int check[] = {
324: PROPOSAL_KEX_ALGS, PROPOSAL_SERVER_HOST_KEY_ALGS, -1
325: };
326: int *idx;
327: char *p;
328:
329: for (idx = &check[0]; *idx != -1; idx++) {
330: if ((p = strchr(my[*idx], ',')) != NULL)
331: *p = '\0';
332: if ((p = strchr(peer[*idx], ',')) != NULL)
333: *p = '\0';
334: if (strcmp(my[*idx], peer[*idx]) != 0) {
335: debug2("proposal mismatch: my %s peer %s",
336: my[*idx], peer[*idx]);
337: return (0);
338: }
339: }
340: debug2("proposals match");
341: return (1);
342: }
343:
1.35 itojun 344: static void
1.27 markus 345: kex_choose_conf(Kex *kex)
1.1 markus 346: {
1.27 markus 347: Newkeys *newkeys;
1.26 markus 348: char **my, **peer;
349: char **cprop, **sprop;
1.27 markus 350: int nenc, nmac, ncomp;
1.61 djm 351: u_int mode, ctos, need;
1.53 markus 352: int first_kex_follows, type;
1.1 markus 353:
1.53 markus 354: my = kex_buf2prop(&kex->my, NULL);
355: peer = kex_buf2prop(&kex->peer, &first_kex_follows);
1.26 markus 356:
1.27 markus 357: if (kex->server) {
1.26 markus 358: cprop=peer;
359: sprop=my;
360: } else {
361: cprop=my;
362: sprop=peer;
363: }
1.1 markus 364:
1.30 markus 365: /* Algorithm Negotiation */
1.1 markus 366: for (mode = 0; mode < MODE_MAX; mode++) {
1.27 markus 367: newkeys = xmalloc(sizeof(*newkeys));
368: memset(newkeys, 0, sizeof(*newkeys));
1.30 markus 369: kex->newkeys[mode] = newkeys;
1.27 markus 370: ctos = (!kex->server && mode == MODE_OUT) || (kex->server && mode == MODE_IN);
1.1 markus 371: nenc = ctos ? PROPOSAL_ENC_ALGS_CTOS : PROPOSAL_ENC_ALGS_STOC;
372: nmac = ctos ? PROPOSAL_MAC_ALGS_CTOS : PROPOSAL_MAC_ALGS_STOC;
373: ncomp = ctos ? PROPOSAL_COMP_ALGS_CTOS : PROPOSAL_COMP_ALGS_STOC;
1.27 markus 374: choose_enc (&newkeys->enc, cprop[nenc], sprop[nenc]);
375: choose_mac (&newkeys->mac, cprop[nmac], sprop[nmac]);
376: choose_comp(&newkeys->comp, cprop[ncomp], sprop[ncomp]);
1.2 markus 377: debug("kex: %s %s %s %s",
1.1 markus 378: ctos ? "client->server" : "server->client",
1.27 markus 379: newkeys->enc.name,
380: newkeys->mac.name,
381: newkeys->comp.name);
1.1 markus 382: }
1.27 markus 383: choose_kex(kex, cprop[PROPOSAL_KEX_ALGS], sprop[PROPOSAL_KEX_ALGS]);
384: choose_hostkeyalg(kex, cprop[PROPOSAL_SERVER_HOST_KEY_ALGS],
1.1 markus 385: sprop[PROPOSAL_SERVER_HOST_KEY_ALGS]);
386: need = 0;
387: for (mode = 0; mode < MODE_MAX; mode++) {
1.30 markus 388: newkeys = kex->newkeys[mode];
1.45 markus 389: if (need < newkeys->enc.key_len)
390: need = newkeys->enc.key_len;
391: if (need < newkeys->enc.block_size)
392: need = newkeys->enc.block_size;
1.27 markus 393: if (need < newkeys->mac.key_len)
394: need = newkeys->mac.key_len;
1.1 markus 395: }
1.7 markus 396: /* XXX need runden? */
1.27 markus 397: kex->we_need = need;
1.53 markus 398:
399: /* ignore the next message if the proposals do not match */
1.56 djm 400: if (first_kex_follows && !proposals_match(my, peer) &&
1.63 djm 401: !(datafellows & SSH_BUG_FIRSTKEX)) {
1.53 markus 402: type = packet_read();
403: debug2("skipping next packet (type %u)", type);
404: }
1.26 markus 405:
406: kex_prop_free(my);
407: kex_prop_free(peer);
408: }
409:
1.35 itojun 410: static u_char *
1.65 ! djm 411: derive_key(Kex *kex, int id, u_int need, u_char *hash, u_int hashlen,
! 412: BIGNUM *shared_secret)
1.26 markus 413: {
414: Buffer b;
415: EVP_MD_CTX md;
416: char c = id;
1.61 djm 417: u_int have;
1.65 ! djm 418: int mdsz;
1.61 djm 419: u_char *digest;
1.62 djm 420:
1.65 ! djm 421: if ((mdsz = EVP_MD_size(kex->evp_md)) <= 0)
! 422: fatal("bad kex md size %d", mdsz);
! 423: digest = xmalloc(roundup(need, mdsz));
1.26 markus 424:
425: buffer_init(&b);
426: buffer_put_bignum2(&b, shared_secret);
427:
1.30 markus 428: /* K1 = HASH(K || H || "A" || session_id) */
1.65 ! djm 429: EVP_DigestInit(&md, kex->evp_md);
1.34 markus 430: if (!(datafellows & SSH_BUG_DERIVEKEY))
431: EVP_DigestUpdate(&md, buffer_ptr(&b), buffer_len(&b));
1.65 ! djm 432: EVP_DigestUpdate(&md, hash, hashlen);
1.30 markus 433: EVP_DigestUpdate(&md, &c, 1);
1.27 markus 434: EVP_DigestUpdate(&md, kex->session_id, kex->session_id_len);
1.26 markus 435: EVP_DigestFinal(&md, digest, NULL);
436:
1.30 markus 437: /*
438: * expand key:
439: * Kn = HASH(K || H || K1 || K2 || ... || Kn-1)
440: * Key = K1 || K2 || ... || Kn
441: */
1.26 markus 442: for (have = mdsz; need > have; have += mdsz) {
1.65 ! djm 443: EVP_DigestInit(&md, kex->evp_md);
1.34 markus 444: if (!(datafellows & SSH_BUG_DERIVEKEY))
445: EVP_DigestUpdate(&md, buffer_ptr(&b), buffer_len(&b));
1.65 ! djm 446: EVP_DigestUpdate(&md, hash, hashlen);
1.26 markus 447: EVP_DigestUpdate(&md, digest, have);
448: EVP_DigestFinal(&md, digest + have, NULL);
449: }
450: buffer_free(&b);
451: #ifdef DEBUG_KEX
452: fprintf(stderr, "key '%c'== ", c);
453: dump_digest("key", digest, need);
454: #endif
455: return digest;
1.1 markus 456: }
457:
1.30 markus 458: Newkeys *current_keys[MODE_MAX];
1.27 markus 459:
1.23 markus 460: #define NKEYS 6
1.26 markus 461: void
1.65 ! djm 462: kex_derive_keys(Kex *kex, u_char *hash, u_int hashlen, BIGNUM *shared_secret)
1.1 markus 463: {
1.15 markus 464: u_char *keys[NKEYS];
1.61 djm 465: u_int i, mode, ctos;
1.1 markus 466:
1.65 ! djm 467: for (i = 0; i < NKEYS; i++) {
! 468: keys[i] = derive_key(kex, 'A'+i, kex->we_need, hash, hashlen,
! 469: shared_secret);
! 470: }
1.1 markus 471:
1.52 markus 472: debug2("kex_derive_keys");
1.1 markus 473: for (mode = 0; mode < MODE_MAX; mode++) {
1.30 markus 474: current_keys[mode] = kex->newkeys[mode];
475: kex->newkeys[mode] = NULL;
1.27 markus 476: ctos = (!kex->server && mode == MODE_OUT) || (kex->server && mode == MODE_IN);
1.30 markus 477: current_keys[mode]->enc.iv = keys[ctos ? 0 : 1];
478: current_keys[mode]->enc.key = keys[ctos ? 2 : 3];
479: current_keys[mode]->mac.key = keys[ctos ? 4 : 5];
1.1 markus 480: }
1.27 markus 481: }
482:
483: Newkeys *
484: kex_get_newkeys(int mode)
485: {
1.30 markus 486: Newkeys *ret;
487:
488: ret = current_keys[mode];
489: current_keys[mode] = NULL;
490: return ret;
1.57 djm 491: }
492:
493: void
494: derive_ssh1_session_id(BIGNUM *host_modulus, BIGNUM *server_modulus,
495: u_int8_t cookie[8], u_int8_t id[16])
496: {
497: const EVP_MD *evp_md = EVP_md5();
498: EVP_MD_CTX md;
499: u_int8_t nbuf[2048], obuf[EVP_MAX_MD_SIZE];
500: int len;
501:
502: EVP_DigestInit(&md, evp_md);
503:
504: len = BN_num_bytes(host_modulus);
1.61 djm 505: if (len < (512 / 8) || (u_int)len > sizeof(nbuf))
1.57 djm 506: fatal("%s: bad host modulus (len %d)", __func__, len);
507: BN_bn2bin(host_modulus, nbuf);
508: EVP_DigestUpdate(&md, nbuf, len);
509:
510: len = BN_num_bytes(server_modulus);
1.61 djm 511: if (len < (512 / 8) || (u_int)len > sizeof(nbuf))
1.57 djm 512: fatal("%s: bad server modulus (len %d)", __func__, len);
513: BN_bn2bin(server_modulus, nbuf);
514: EVP_DigestUpdate(&md, nbuf, len);
515:
516: EVP_DigestUpdate(&md, cookie, 8);
517:
1.58 djm 518: EVP_DigestFinal(&md, obuf, NULL);
1.57 djm 519: memcpy(id, obuf, 16);
520:
521: memset(nbuf, 0, sizeof(nbuf));
522: memset(obuf, 0, sizeof(obuf));
523: memset(&md, 0, sizeof(md));
1.1 markus 524: }
1.26 markus 525:
526: #if defined(DEBUG_KEX) || defined(DEBUG_KEXDH)
527: void
528: dump_digest(char *msg, u_char *digest, int len)
529: {
1.61 djm 530: u_int i;
1.26 markus 531:
532: fprintf(stderr, "%s\n", msg);
1.37 deraadt 533: for (i = 0; i< len; i++) {
1.26 markus 534: fprintf(stderr, "%02x", digest[i]);
535: if (i%32 == 31)
536: fprintf(stderr, "\n");
537: else if (i%8 == 7)
538: fprintf(stderr, " ");
539: }
540: fprintf(stderr, "\n");
541: }
542: #endif
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